Moisture control system



April 11, 1944; R 2,346,437 v MOISTURE CONTROL SYSTEM Filed Aug. 10,1939 5 Sheets-Sheet 1 FIG. I.

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\NVENTOR ANKER E. KROGH ATTORN EY April 11, 1944. E, KROGH 2,346,437

' MOISTURE CONTROL SYSTEM Filed Aug. 10, 1939 5 Sheets-Sheet 2 93INVENTOR ANKER E. KROGH ATTORNEY April 11, 1944.

A. E. KROGH MOISTURE CONTROL SYSTEM Filed Aug. 10, 1939 5 Sheets-Sheet 3INVENTOR ANKER E. KROGH ATTORNEY April 11, 1944. E KR GH 2,346,437

MOISTURE CONTROL SYSTEM Filed Aug. 10, 1939 5 Sheets-Sheet 4 FIG. 7.

INVENTOR ANKER E. KROGH BYM ATTO R N EY April 11, 1944. E KROGH2,346,437

MOI STURE CONTROL SYSTEM Filed Aug. 10. 1939 5 Sheets-Sheet 5 INVENTORANKER E.KROGH WW ATTORNEY Patented Apr. 11, 1944 MOISTURE CONTROL SYSTEMAnker E. Krogh, Mount Airy, Pa., assignor to The Brown InstrumentCompany, Philadelphia, Pa., a corporation of Pennsylvania ApplicationAugust 10, 1939, Serial No. 289,404

43 Claims.

The present invention relates to apparatus for controlling the moisturecontent of various materials, and more particularly to the preparationof'yarn in a slasher as it is wound on a loom beam preparatory to theinsertion of the latter into a loom in which the yarn is incorporatedinto a woven fabric.

The so-called slashing machines used for sizing and drying the yarn asit is wound on a loom beam consist, in general, of supports for the warpand loom beams, a pan or trough for containing the sizing material andsqueezing rolls between which the yarn passes afte it has been size'd,steam heated drying rolls or drums over which the yarn passes afterbeing sized and before it is wound on'the loom roll, and some means todrive the drums. Quite often a slasher is also supplied with a so-calledspider fan which forces air past the dried yarn and a hood over thedrying drums through which the moisture driven irom the yarn isexhausted. Each of these component parts of a slasher has its own effecton the moisture content of the yarn as it is wound on the loom beam.

For the attainment of the best results in the weaving process it isessential that the yarn have the proper moisture content. This contentis expressed in percentage and may vary over a narrow range, the rangechanging with the type of yarn. It is a general object of the presentinvention to control the operation of the various component parts of aslasher so that the optimum value oi moisture content oi the yarn may beobtained.

It has been the custom to control the pressure or temperature of thesteam in the drying drums in an attempt'to control the moisture content01' the yam' on a slasher. This has not, however, been satisfactorysince the steam pressure along with other variables such as size boxlevel and temperature, atmospheric temperature, fan speed and yarntension are at best mere stabilizing conditions. In order to deliveryarn at uniform moisture, an ideal control system must compensate forall variables, some of which cannot be stabi- H2611. The control of mysystem compensates for all of the variables by measuring the actualmoisture content of the yarn and varying the speed or the slasher tokeep it at a maximum safe operating value at all times.

In the operation of the system a very small current flows through theyarn and is detected by a modified bridge circuit, which is continuallykept n balance by a motor driven slide-wire withinthe instrument. In theinstrument are also a pair of motor driven contacts which in turncontrol the speed of the slasher.

At all times there is considerable yarn on the slasher drying drumswhich will not feel the full effect of a speed change. Only that yarnwhich enters the size box after the speed change has been made will feelthe complete effect of it, hence, it is important following, a speedchange that no further changes he made during the time the moisturemeasuring instrument is actually measuring the yarn that has ielt thefull effect. For this purpose an electrical interrupter is at-- tachedto the slasher and is so constructed that the circuit to thetransmission control motor is completed at intervals sumcient to permitthe slasher to be completely stripped of yarn before another change ismade. If the moisture measuring instrument shows that the change wasinsuficlent an additional speed change is produced. By driving theinterrupter from the measuring roller on the slasher, this system adaptsitself to various yarns regardless of the required speed.

Since it is not desirable to change the normal slasher speed due tostopping or slow motion of the drums a switch is operated by the slashershifter handle which operates to disconnect the control system. When theslasher switch is returned to its running position the control againstarts to function but in order to permit the baked yarn on the slasherto he removed before speed changes are instituted a time intervalelapses bei'ore a timing unit operated by the switch, closes itscontacts and full control is re sumed.

It is an object of this invention to provide a highly accurate means tocontrol the speed of the drying drums of a slasher in response to themoisture content of the yarn being wound on a loom beam so that the yarnmay remain for a longer or shorter time in contact with the drums. Ameasurement of the yarn's moisture content is made and the speed oi thedrums controlled intermittently in response to this measurement.

It is a further object of my invention to reduce the pressure of thesteam supplied to the drums when the slasher is stopped to preventoverdrying of the yarn that is at that time in engagement with thedrums. It is a further object of my invent on to control other variablesin the slashing process such as the speed of the spider fan, the spee iof the exhaust fan in the hood, and the tem perature of the size incombination with the speed control of the drying drums.

The various features of novelty which eharac terlze my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, its advantages and specific objects obtained with its use,reference should be had to the accompanying drawings and descriptivematter in which I have illustrated and described a preferred embodimentof the invention.

In the drawings:

Fig. 1 is a diagrammatic side view, partly in section, of the controlsystem of my invention;

Fig. 2 is a top view, partly in section, of Fig. 1, with certain of theparts omitted:

Fig. 3 is a wiring diagram of my control system;

Fig. 4 is a wiring diagram of a less elaborate y Fig. 5 is a view of theslasher driven interrupter;

Fig. 6 is a diagrammatic view or the system as used when more than oneslasher unit is driven from the same power supply;

Fig. 'I is a view of my control system combining speed and exhaust fancontrol; 7

Fig. 8 shows another type of exhaust control;

Fig. 9 is a view of my invention combining speed and steam pressurecontrol;

Fig. 10 is a view of my invention combining speed and a difierent typeof steam pressure control;

Fig. 11 is a view of my invention combining speed and spider fancontrol; and

Fig. 12 is a view of my invention combining speed and size temperaturecontrol.

Referring to Fig. 1 yarn is led from the right from a warp beam (notshown) around the rollers 2 in a size tank 3, over drying drum d and 5,guide rollers B and l and past a guide roller 8 to be wound on a loombeam (not shown). 00- operating with the guide roller 6 is a measuringroller 9 which is electrically connected to 9. moisture measininginstrument M; the details of which will be described below.

Size is admitted to the tank- 8 through a line it) that has a valve init which may be operated automatically, if desired, by any suitablemeans to maintain the size level constant. The temperature of the sizeis kept constant at some predetermined value by means of a temperaturecontroller i i in order that the viscosity and penetratin power of thesize may remain the same. The instrument ii, shown as a Brownair-operated controller, is responsive to size temperature by means of atemperature responsive bulb 12 in the tank 3 and a connecting capillaryi3. Air under a suitably constant pressure is supplied through a pipe 84and is .varied by the instrument ii to apply difierent pressures on thediaphragm of an air operated valve 95 to thereby vary the opening ofthat valve and accordingly change the admission rate of heating steam tothe size tank.

Steam is supplied to the valve iii and tank 3 through a line is whichalso supplies the heating steam to the drying drums and b. In order tomaintain the pressure of the steam in the drying drums constant an airoperated valve ll of the spring closed type is used. The air pressuresupplied to the diaphragm of this valve is regulated by an air controlpressure controller iii that is normally supplied with air through aline 99 having a pressure regulator is in it. As the galue of thepressure in the drying drums changes the pressure applied to thediaphragm of valve ll through line at is altered by the controller is tovary the opening of valve ill. A second air line asaaesv 22 supplyingair to controller iii is in parallel with the line it and is providedwith a pressure regulator 23 that is set at a much. lower value than theregulator 2@. At times during the operation of the system a solenoidvalve 26 in the line It is closed, thus supplying air to controller isthrough line 22 at a lower pressure. The result of this is that thespring of valve ll will tend to close that valve and reduce the steampressure in drums 4i and 5. The manner in which the valve 26 isoperated'will be described below in the operation of the system.

During the slashing process the efilciency of the slasher is increasedappreciably if the moisture driven from the yarn is removed. In order toaccomplish this a hood 25 is located over the drying drums and the sizebox and is provided with an exhaust duct 2t having an exhaust fan 27located in the duct, driven by a motor 28.

A spider fan 29 driven at a suitably constant, but variable, speed bythe motor its is located so that its blast passes over the yarn after ithas left the drying drums and before the yarn is engaged by measuringroller 9. This fan 29 may have some small drying function, but its valuelies chiefly in removing loose particles of size and lint from the yarnbefore it is wound upon the loom beam.

The drying drums 4i and 5 are driven at various speeds depending uponthe moisture content oi the yarn passing under roller 9 by means of amotor Eli and a variable speed transmission 3d of the Reeves type. Fastand loose pulleys 35 on the shaft of the motor 38 transmit its powerthrough a belt 32 to the pulley 33 of the driving shaft 35 of thetransmission. A variable speed transmission of this type consists ofdriving and driven shafts fill and Bil, respectively, each having anexpansible conical pulley and 38 upon it. These pulleys are connected bya belt 3Q so that shaft 36 is driven by shaft ill at a speed dependentupon the relative sizes or pulleys ill and 88. The sizes oi the pulleys,and thereby the speed of shaft 36 may be changed by pivoting rods to,which are connected to the pulleys, around their center points. This isaccomplished by having the outer ends of the rod it in threadedengagement with right and aft hand threads of a screw shaft 4H that isrotated by reversible motor 63. The motor as is controlled frominstrument M. The transmission drives the drying drums d and 5 from theshat 36 by means of gears 42 connecting that shaft and the shafts of thedrums.

The belt 32 may be shifted from the fast to the loose pulley ill bymeans of a manually operated shipper rod it which is provided with aprojection 65 that'is adapted to adjust the position of a switch asduring its movement.

0n the shaft :3 of the drum 3 there is another pulley 67 which, througha belt 38 drives a shaft 69 of an interrupter so to periodically openand close the circuit from the measuring instrimient to the motor 68 ina manner to be described in detail below. The interrupter serves thefunction of and may be called a speed responsive element since theclosing or the switch thereof is in response to the speed of the slasherby which it is driven.

The slasher driven interrupter E563 is illustrated more in detail inFig. 5. The shaft 69, through suitable gearing 5i, drives shafts E52 andE33, at rates depending upon the slasher speed. Mounted on shaft 52 aretwo cams sea and ME which when taken together, form a single cam 6dwhose low portion may be varied in extent by placing a pin 55 in anopening in cam 54B and one of a series of openings in the cam 54A. Onshaft 53 is a cam 55 that, because of the gearing BI, i rotated at amuch slower speed than is the cam 55. Below and between the cams is ashaft 51 upon which is mounted a bell-crank 58 that is normally biasedin a clockwise direction by spring 59. The lever 58 is provided on eachof its arms with a cam following roller, one. for each of the cams 54and 56, and is provideo below its pivot with a bracket 50 adjustablyi'astened thereto and supporting a mercury switch 6|. The arrangement isuch that as the cams rotate their respective low portions willperiodically come under the cam following rollers to Permit lever 58 tomove clockwise and close switch The cam 55 is driven by the gearing fromthe slasher at such a speed that its low portion comes under its rolleronce for approximately every twenty yards of yarn that move over thedrying drums. The cam 54 is so adjusted that the switch BI is permittedto stay closed for some predetermined length of time. The switch BIcontrols the time of operation of the speed adjusting motor 43 in amanner.

presently to be described. a

The particular type of moisture measuring instrument disclosed hereinforms no part of my invention except in combination with the rest of themeasuring and controlling system. Referring now to Fig. 3 there is showna wiring diagram in connection with which will be explained theoperation of the system.

An electric measuring and amplifying circuit by which the moisturecontent of the yarn I may be measured in order to control theenergization of motor 43 and the speed of the slasher comprises a firstbalanced Wheatstone bridge arrangement, two adjacent arms of whichinclude similar electronic valves 62 and 53, respectively, which may beheater type triodes whose heating elements 62a and 83a may be energizedfrom any suitable source. The other two bridge arms include resistances64 and 85. The opposed normally equal terminals 66 and 81 of the bridgeare connected by conductors to the terminals of a center-zerogalvanometer B8. The other two opposed junctions 69 and 10 of the bridgecircuit are connected to a suitable source of direct current which isdiagrammatically shown by the plus and minus marks.

A second Wheatstone bridge electrically connected to the first includesthe web moisture measuring connections which comprise the roller 9 thatis spring-biased into engagement with the yarn I by a spring II. Theresistance of the yarn I between the roller 9 and the roller 8, which isshown as being connected to the bridge, is variable and responsive tothe moisture content of the web I. The normally equipotential junctionsI2 and I3 of the second bridge are connected to the grids 62b and 63b ofthe triode elements 52 and 53, respectively. The othe two junctions 14and of the second bridge are connected to the junctions 69 and III,respectively, of the first bridge, the junction 15 being connecteddirectly and the junction 14 being connected through a biasingresistance I5. The points 13 and 14 and 13 and 15 are connected.respectively, by fixed resistors 11 and I8, while the points I2 and 14are connected by a variable resistance I! which is adjusted to rebalancethe bridge when it is unbalanced by a change in the resistance 01' yarnI. Both of the bridges 'line, the resistance iii beii have a groundconnection on the positive side at 80.

The bridge junction 69 is connected through the resistance 716 to thenet tive side of the of such value that each or the grids 62b 6% hasnotch-= tial which is negative with respect to the potential of thecorresponding cathodes 62c and 880, respectively.

In operation with the normal balanced condition of the bridges, thegrids and 585 are similarly negative relative to respective cathodes 62cand @530, the similar triodes (3E and 63 are equally conductive, currentflows through the bridge arm and are equal and the bridge junctionpoints 38 and iii! are therefore at the same potential, and pointer 68aof the galvanometer will be in its neutral position. On a decrease inthe moisture content of the yarn i in; contact with roller 9, the creasein the value of the resi 'ance between rollers 8 and 9 results in anincr potential drop in that leg of the bridge, and time ncreases theextent to which the grid 62b is negative rein tive to cathode 620. Thisdiminishes the conductivity of the triocle (B2 and makes the potentialof the bridge junction 536 higher than the potential of junction 6?.Furtherr ore, the po tential difference between the b e junctions B5 and51, due to the increa oi otial drop between junctions l2 and b amplifiedsince the decrease in the current v through the triode 62 decreases thecurrent now through the resistance l6, and increases the potential ofthe grid 6% in a no this direction relative to the potential of thecorrod to make the triode 83 more conductive. The re sultant increasethrough the resistance lowers the potential of junction 6?. @onversely,an increase in the moisture content of the I and the resultant reductionresistance increases the potential of the junction point and decreasesthe potential of ions point The pointer 68a of the galvano er willdeflect In one direction or the titer from its neutral position as thepotential. of bridge junction 86 rises above or falls below thepotential of junction 51, and the deflect? to position of this pointeris relied upon to mechanism which will indicate and record the of themoisture content of the yarn i. For this purpose, the end of pointer 38ais provided with a contact that, upon deflection of the salve-nometer.will engage one of contacts Gin or 8th to energize one field or theother of a reversible motor 8| that is used to rebelance the bridge andmove a pen and indicator.

A contact 719a has attached to for movement with it a combined pen andindicating element 19b that is moved, respectively, along the resistance79, the chart 82 and scale 83 the motor BI in response to unbalance ofthe bridge circuits as a result of a change in the moisture content ofthe yarn l. The rotor till is energized by a deflection or" thegalvanometer pointer 68a in a direction to move the contact lilo torebalance the bridges. Attached for movement with, but insulated from,the is a cow tact 84 which is adapted to brought into engagement withone of a pair of contacts 85a or 8517 mounted on a block The reversiblemotor 43 that is used to adjust the transmission 3d is energized forrotation in one direction or the other as the contact O l is mov d inment with one of the contacts 'r i this manner, as the bridge circuitsare unbalanced as a result of a change in moisture content of the web t,the motor M will be energized to rebalance the bridge and move a pen andindicator across a chart and scale, respectively to record and indicatethe value thereof. This movement is also used to adjust the transmission34 by means of motor $3 in an amount and direction to change the speedof the drums d and 5 so that they will return the web to its normalmoisture content.

The block 85 to which contacts 850. and 85b are attached is mounted on ascrew threaded mem ber 85 so that these contacts can be shifted withrespect to contact M in order to change the control point of theinstrument, or to change the moisture content which the instrument willtend to keep in the web.

In order that the speed of the slasher is intermittently adjusted inaccordance with the length of yarn that passes the drying drums suitableinterrupters are provided in the circuit from the contact as andcontacts the and 85b and the motor 63. This is done so that the eiiectof each speed change may be measured by the instrument Mbefore'succeeding speed changes are made.

Ihe motor 63 is supplied with current from a suitable A. C. line througha transformer 81. One side of the transformer 87 is connected directlyto the motor 43 by line 88 and the other side is connected through line89, slow push button 90, fast push button 9i, interrupter switch 6!,stop switch illl and line 92 to contact ed. The contact 85b is connecteddirectly to the field dab of motor 43, which field is used to slow downthe slasher speed, by line 93. Contact 85a is connected by line 9 3,normally closed switch 95 and line as to field lieu; of motor 33, whichfield is used to rotate the motor in a direction to speed up theslasher.

In the normal operation of the instrument the moisture content of theyarn is continually measured and recorded. As the moisture varies thecontact 86 will engage either contact 85a or 852) to cause rotation ofthe motor 423 in the proper direction to adjust the variable speedtransmission in order to change the speed of the slasher to compensatefor these variations. The interrupter switch Bl, operated by theslasher, is periodically opened so that after each speed change the yarnthen on the drying drums will have been removed so that the full efiectof the speed change may be known before another change is made. Sinceswitch 6i is driven from the slasher roll it will always be operated insynchronism therewith to insure that the proper amount of yarn haspassed.

When, in order to stop or slow down the slasher for any reason, theshipper rod id is moved to shift belt 32 to the loose pulley, itsprojection 35 will operate switch iii? to move it from the positionshown in Fig. 3 into engagement with the lines 91!. This movementperforms two operations. First, the bridging of lines 9? shunts out partof resistance it in the bridge circuit so that the bridge will becomeunbalanced and motor 8i will move the pen down scale. As the pen movesdown scale a projection 98 on the pen carriage engages switch support 99to tilt it against the bias of its spring to open switch ltd anddeenergize the solenoid valve 2d thus closing on air line it to thepressure controller is. Low pressure air through line 22 is thensupplied to the controller and valve ii to permit that valve asi es? toclose under its spring pressure and reduce the steam to the dryingdrums. In this manner the temperature of the rolls is reduced to preventundue baking of the yarn while the slasher is at rest or running slowly.

Secondly, the moving of switch 38 to its upper position of Fig. 3deenergizes relay HM so that its switch member lilla may drop to its lowposition. This first opens line M2 to deenergize relay W3 so that switch$35 may open and disconnect the fast neld 43a oi motor 53 from theinstrument. This is necessary because when the drum temperatures arereduced and the slasher is stopped the yarn will be wet. Therefore it isnecessary that the setting of the igansmission is not altered in adirection to speed up the slasher as yam will not be dry enough beforethe slasher speed can be reduced as the slasher is started.

In order to further insure that the transmission setting will be at asufficiently low value when the slasher is again started provision ismade upon the deenergization of relay Bill to reduce the setting of thetransmission by ener gizing the slow field 53b of motor 43 for a shortwhile. This is accomplished by energizing a time delay relay it throughthe line we when the upper bar of the switch member iilla closes thatline. A circuit from the transformer through line 88, field 432), linestilt, till, switch ltd, line W9, push buttons 9i, 9d and line tit baclsto the transformer is then completed. Motor #38 then runs in a directionto reduce the transmission setting until a bimetallic element it lcforming part of relay 584, is heated sumciently for its upper end tomove to the right enough to open the switch Hi8. c

Upon restarting the slasher the shipper bar B6 is shifted to place belt32 on the fast pulley 3i.

This moves switch :36 back. to its position of Fig.

3 to energize the relay lfli, and replace the full value of theresistance it in the bridge circuit. Current builds up slowly in therelay lili so that before the switch member this has moved to its upperposition to close the circuit to relay M3 the yarn that has been on thedrying drums during the time the slasher was stopped has been removed.Thereafter the speed oi the slasher is controlled in accord nice withthe reelsture content of the yarn as the interrupter switch ti isclosed.

Manual operation of the speed changing motor 53 may be performed at anytime by pressing button to slow down the speed of the slasher and bypressing button ti to speed. it up. If it is desired to entirely removethe automatic control of the slasher speed the switch Mil in series withthe interrupter 66 may be manually opened. thus breaking the common leadiii? to the control instrument M.

A short summary of the operation oi the system will now be given. Whenthe slasher is at rest the switch member 416 will be bridging lines 91and the pen carriage ltd wiil be at the dry end of the instrumentholding switch tilt open so that steam under low pressure is admitted tothe drying drums. The relay i166 has been energized long enough so thatswitch tilt is open and relay iii-3 is deenerglzed so that switch 95 isopen. Therefore, the set ing oi the transmission M can only be changedmanually by push buttons at and 95.

Upon moving the shipper rod l t to start the slasher the switch memberis moved to its position of Fig. 3 and the instrument ivi immediatelystarts to measure the moisture content of assess? the yarn. By the timethe yarn that was on the slasher drums during the stopping period hasbeen removed current has built up in relay m sufficiently to movecontact member lflla to its position of Fig. 3 to energize relay I03 andclose switch 85. Thereafter the instrument controls the slasher speedand moisture content of the yarn by energizing the motor 43 for rotationin the proper direction.

Upon stopping of the slasher, switch 46 shunts out part of resistance 18oi. the measuring circuit and deenergizes the relay NH. The effect ofthe latter is to immediately deenergize relay I03 to open switch 95 andto close a circuit through field 43b of motor 43 to run that motor in adirection to reduce the setting of the transmission. Simultaneously withthe last operation the coil of relay I04 starts heating up and in a fewseconds causes bimetallic strip iMa. to open switch I08 and stopmotor43. The system is now again in its original condition.

The wiring diagram shown in Fig. 4 is similar in most respects to thatshown in Fig. 3. Current is supplied from the line through a switch III,that when opened shuts down the entire system. Connected across the lineis the switch 48 and the coil of a time delay relay H2, that is designedto open quickly and close a predetermined time after its coil isenergized. Upon opening of switch 46 as the slasher is stopped the lines81 are bridged, as was done in the embodiment of Fig. 3, to force thepen to move down scale and open switch Hill to reduce the steam pressurein the drying drums.

The interrupter switch 6| is also in this embodiment operated by theslasher so that the interrupting periods will be based upon the speed ofthe slasher rather than upon an arbitrary time. This has the obviousadvantage that control impulses may be given the transmission speedcontrol motor 43 more or less frequently according to the requirementsof the process so that the instrument M can detect the full effect of aspeed change before a subsequent change is made.

In this embodiment the fields of the motor 48 are shown provided withlimit switches H3 and H4 that may beset at a point to limit the maximumand minimum'speeds oi the slasher. It is noted that the motor ofFlg. 3may also be provided with similar switches if desired.

In the operation of this embodiment the switch ill is closed and theshipper rod is moved to a position to close switch 46 and start drivingthe slasher. A short time, depending upon the amount of yarn on drums 6and 5, after the slasher is started relay H2 will close its contacts H5.Thereafter as the moisture content oi the yarn differs from that forwhich the instrument is set to maintain the fields 63a or 311 of motor43 will be energized to change the setting of the transmission. Aftereach control period the interrupter switch ti will be opened for alength of time depending upon the speed of the slasher so that the iulleffect of the speed change may be determined before a subsequent changeis made. The motor it may be rotated in either direction at any time bythe manual operation of switches at or 99.

In the embodiment of the invention just described it was assumed thatthe slasher was driven from its individual driving motor 36. In sometextile mills, however, it is customary to drive several slashers from asingle motor by means of a common shaft. When this is done there will bea variation in speed of the remainlog slashers due to the load changewhen one of them is taken oft or the line. ouch a speed change of thedriving shaft of the transmissions will cause a change in the speed ofthe slasher driving drums and 'therctor t the mele ture content of theyarn in order to overcome this obviously undesirable condition 1 haveprovided a means to compensate the speed of driven shaft 38 0! thetransmissions for variations in speed of the driving shaft Referring toFig. a, there is shown one com pensating unit in detail. to beunderstood that a similar unit may be use tor each of the slashercontrol systems, or a single unit, with proper connections, may be usedfor all of the slashers driven by the same shaft. in that figure thereis shown a shaft Mtthat is driven by any suitable means, which shaftserves to drive the transmission units of plurality of slashers.Attached to the shaft is a hovel gear iiti that through a similar geardrives the shaft ill of a fiy-ball governor. Fixed to the lower end ofshaft H1 is a collar lid and slidably mounted near its upper end is acollar Mil that is normally forced upward by a, spring ltd and is moveddownwardly by the halls tilt as the shaft Ill increases in speed.Five-tally attached to the collar H9 is a lever 1122 whose opposite endis pivoted on a collar [123 that is adjustably secured in position on asupport i12 extends parallel to the shaft ill. As the lever G22 movesclockwise and counter-clockwise around its point of attachment to thecollar i253 due to slowing down or speeding up of the shaft iii a resultof a change in load thereon, a three-armed lever 02$, pivoted at W, ismoved accordingly due to a connection between on the lever i126 and aslot l22a in the lever Control of the transmission adjusting motor 43from movement of the lever is obtained by means of a contact M8 on oneof the lever I25 and contacts i225 B35) are supported on a movablebloct: ifii. "lice blocl: is mounted for sliding movement in thestationary bearings I32 and is provided on. one of its faces with a rackthat is by a pinion is driven through a .c clutch comprising drivingdisc lilla and driver also which take the form of elec' cmagnetic fromthe motor 43 as it rotates. The third arm of lever H5 is formed as apointer that cooperates with a scale Ht which may" he provided withcalibra= tilosn marks corresponding to the creed of shait In theoperation shait l is dllV- ing all of the slashers that connected Whenone of the slashers stopped the load on the shaft will be reduced sowill tend to speed up. This will cause E'JGVGi'XlOi balls tilt to movefurther apart and move collar M9 down wardlyi to rotate lever H82C'Olll'iliGE- ClGCYKV/lSG around its pivot on collar 623, which movementwill rotate lever 625 counties-clockwise to bring contact I28 into withcontact 68%. The contact is connected to one side of the line by a.condiictor includes the winding oi the magnet in clutch c b, and contacttilt) is connected to the lin 2;; from the in strument M to the slow vof the motor G3, so that upon engagement oi contacts the motor 43 isenergized for rota on in. a direction to slow down the shaft 536 oi thetransmission. Motor 43 will continue run until the hiccl; lill has beenmoved downwardly enough by the pinion m, driven by the clutch from motort3,

to open the contacts F28 and At this time the shaft 36 of thetransmission is running at the same speed that it was prior to the timethe slasher was disconnected from shaft M5.

It will-be obvious that when the slasher that was stopped is againstarted the increased load will tend to slow the shaft H5 down. Thiswill initiate an operation opposite to that just described to bringcontacts 828 and 529 into engagement to energize field 53m of motor 63.When the speed of shaft 36 has been corrected to compensate for thechange of speed of shaft M5 the contacts 828 and 62?} will be separatedby upward movement of the block 53d. The initial aiustment of the collar823 along support i2 5 may be changed as desired so that the apparatusmay be adjusted for different normal speeds of the shaft M5. The normalspeed of shaft H5 may be varied in any suitable manner to take care ofdiflerent types of yarn on the slashers.

As the motor 63 is energized by the instrument M the position of contactcarrying block. I35 will not be altered since the clutch liif'ia, i331;is energized only when a circuit is closed through contact H8 and one ofcontacts 625! or 93d As has previously been stated various other factorsbesides the speed of the drying drums enter into the drying of the yarn,and at times it may be desirable to control others of these factors inaddition to or'in conjunction with the speed of the drums.

In th operation of a slasher considerable steam rises from the sizeboxes and the yarn and the amount of drying obtained depends in partupon the amount of dry air pulled past the yarn by means or the hood 2band the exhaust fan 2'6. By controlling the speed of this fan the dryingefiect on the yarn by the drums l and ii can be varied. Such anarrangement is shown in Fig. 7 in which a variable speed motor 28a isused to drive the exhaust fan 27!. The speed of the motor 28a may bevaried by moving a contact i236 along a resistance M35 in the motorcircuit. This contact is moved by a reversible motor 536 that is inparallel with and energized simultaneously with the energization oftransmission adjusting motor 63 as contact 86 in the instrument Mengages either of contacts tile or set.

In this embodiment the arrangement is such that ii the instrument Mindicates that the yarn is too dry the motor 33 will be rotated in adirection to speed up the drums d and i5 and the motor i135 will at thesame time be rotated in a direction to shift th 'contact H36 to theright along the resistance i235 and slow down the fan motor 28a. In thismanner a double effect is applied to the drying operation and it may notbe necessary to vary the speed of the drums as much as when the latteris alone used to control the drying. This embodiment also has the addedadvantage, as do other embodiments to be described below that theslasher may be run more nearly at its full speed at all times.

In Fig. 3 there is shown another means for accomplishing the sameresult. Instead of varying the speed of the fan 2?! a damper Hill in theexhaust duct is opened or closed to vary the volume of exhaust air. Thedamper till is formed on one side of its lower end as a rack that mesheswith a pinion its driven by a reversible motor M39. The motor 089 isalso energized by the instrument M along with the motor 53. Thearrangement is such that as the motor 33 is enerized tor rotation in adirection to slow down assess? the drums the motor 339 will be rotatedin a direction to lower the damper i3? and permit more air to be drawnpast the yarn. In this manner the drying process is increased inresponse to a measurement showing that the yarn was too moist.

As is well known, the drying efiect of a cylinder depends upon itstemperature, which i in turn dependent upon the steam pressure withinthe drying drums. While it is generally desirable to maintain thetemperature of the drying drums constant and vary their speed as hasbeen above described, there are times when it may be of advantage tovary the steam pressure in the drums in conjunction with their speed.Such an arrangement is diagrammatically shown in Fig. 9. The recordingpressure controller 98, which has been described above is used toregulate the valve ill and thereby the pressure in the drums (l and E5,may well have the control provisions described and claimed in Patent2,125,081 issued to C. B. Moore and is now in extensive commercial use.An instrument of that type has provisions for adjusting the pressurewhich is to be maintained to different values, and while such anadjustment may be made manually it is, for purposes of this invention,more convenient to make by means of a small reversibl electric motorthat is energized by the instrument M when motor 63 is energized.

In the operation of an interlock system of this type as the moisturecontent of the yarn is, for example, low the instrument M will energizemotor 33 for rotation in a direction to speed up the drying drum andwill simultaneously energize the control setting motor in the instrumentiii in a direction to lower the controlpoint thereof and reduce thesteam pressure in the drying drums. Because of the fact that both thespeed of the drums and the steam pressure therein are varied it isnecessary to maize only small adjustments of each in order to obtain thenecessary correction in the moisture content of the yarn.

' Instead of varying the steam pressure in the drying drums along withtheir speed said pressure variations may be used only after the speedchange mechanism has reached the limit of its movement. In this mannerthe range oithe system may be extended appreciably. An arrange-- mentfor doing this is shown. in Fig. 10 wherein the motor driven valve Mb isused to control the pressure in the drums instead 01 the valve illpreviously described. The opening of valve 869 is adjusted by means oi asegmental rack ili and a pinion its that are driven by a reversiblemotor MB. This motor is supplied from one side or the line through aninterrupter E 365, through switches M5 or M6 to the other side of theline and is so arranged that when switch M35 is closed the valve will bemoved in a closing direction and when switch is closed the valve will bemoved in an opening direction. The interruptor Hill may be operated toclose the circuit at equal intervals or time, but is preferably drivenfrom the shaft li along with the interrupter 59. If desired the supportso of the interrupter 50 may have a second switch attached to it, whichsecond switch. forms the interruptor MG.

In the operation or: this embodiment as the speed control motor 33 isadjusted a lever id? is moved thereby in such a manner that as the motorreaches its maximum or minimum positions,.respectively, the switchesllll or MS will be closed to energize motor M3 to adjust the aerate?opening of valve i ili. If, for example, the yarn is unduly moist as itpasses the measuring roller a the instrument M will cause motor $3 to beenergized in a direction to slow down the speed oi the drums 4i and 5,at the same time moving lever Nil clockwise. After the motor 433 hasbeen run to adjust the transmission M to its minimum speed limit, thelever Ml will close switch M5 to energize the motor M3 for rotation in adirectionto open the valve Mil. The motor, due to the interrupter HMwill be run in steps to increase the steam to the drums only after ameasurement has been made to show the effect oi a previous adjustment onthe yarn. If an adjustment of the valve Md was such that the yarn isdried too much the motor li-i will be energized to slow down thetransmission and the drums and at the same time will move lever i l'lcounterclockwise to open switch Mil. Thereafter until the motor 43 hasreached one or the other of its limits the steam pressure in the dryingdrums will be maintained at its new limit. In a like manner if the yarnis unduly dry the lever Hl'i on motor 43 will be moved counter-clockwiseuntil switch I45 is closed. At that time motor M3 will be intermittentlyoperated to reduce steam pressure in the drying drums,

Another method of controlling the moisture content of the yarn on aslasher is by simultaneously adjusting the speed of the drying drums andthe speed of the spider fan 29. The air entering the fan to be blownover the yarn is usually heated by radiation from the larger drum 4 and,therefore, has an influence on the moisture remaining in the yarn,although such influence is generally less than that of the exhaust fan2?. As shown in Fig. 11 the spider fan 29 is driven by a variable speedmotor 2% that is supplied with current through a variable resistance M8whose value can be changed by movement of the contact M9 therealong.This contact is moved in one direction or the other by a reversiblemotor 559 which is energized from the instrument 1M? dong with motor M3.

in operation if the yarn is too dry the motor &3 will be energized forrotation in a direction to speed up the drums and at the same time themotor idd will be energized for rotation in a direction to shift contactM9 to the right along resistance M8 and slow down the motor 2%. In likemanner if the yarn is too wet the drying drums will be slowed down andmotor iiitl will be energized in a direction to shift contact M9 to theleft and speed up the motor 2% so that fan 29 will force more warm airover the yarn.

Still another interlock system that may be used to control the moisturecontent of yarn is shown in Fig. 12 in which the speed or the dryingdrums is controlled in conjunction with thetemperature of the size box.The temperature of the size has an influence on the amount of moistureremaining in the yarn by the time it reaches the drying drum 6. This isbecause a high temperature naturally induces more evaporation. As isshown in Fig. 12 the size box 3 is heated by an electn'c heater i5!whose heating effect is varied by moving the contact i522 along theresistance E53. The contact is adapted to be moved in the properdirection by means of a reversible electric motor I54 that is energizedfor rotation along with the motor it by the instrument M.

If the yarn is too dry the motor 53 is energized for rotation in adirection to speed up the drying drums and at the same time motor ledrotated in a direction to move contact 652 upwardly along resistance itito thereby reduce the temperature of the size. In a like manner it theyarn is too moist the drums Li and ii are slowed down and the sizetemperature is raised.

While I have described the regulation 01. the size temperature by theadjustment of an electric heater it will be obvious that a controller ofthe type shown at i i in Fig. 1 may be used if desired.

If that is the case the control point of the con-' troller it will beadjusted by an electric motor as was the control point of the controllerIII in Fig. 9.

In the above detailed description various means have been disclosed forcontrolling the drying process or yarn in a slasher. It will beunderstood that the various control instrumentalities may be used singlyor with each other in other combinations than those disclosed ifnecessaryor desirable. It will be obvious that the addition of a controlfor one or more of the variables in the slashing process to any of theother controls in order to obtain a better product may be accomplishedwithin the scope of my invention. Each of the variables in the processthat is controlled cooperates with the others to produce a more uniformproduct, and those variablesthat are controlled together may be selectedin accordance with the type of yarn being handled, the percentage ofmoisture that is to be kept therein and various atmospheric and plantconditions that afiect the process and cannot be controlled.

The term yarn that is used herein and in the appended claims is meant toinclude both natural and artificial threads such as cotton, wool, rayonetc.

Attention is also calleolto the fact that while the control system isdescribed for use in connection with a slasher for drying yarn that thesame system is equally adaptable for use with systems for drying anytype of wet material in which the speed of the material passing thedrying means may be changed.

While in accordance with the provisions of the statutes, I haveillustrated and described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in the form or" the apparatus disclosed withoutdeparting from the spirit or" my invention as set forth in the appendedclaims, and that certain features of my invention may sometimes be usedto advantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire tosecure by letters Patent is:

1. In a slasher control system wherein the slasher is provided withheated drying drums over which the yarn to be dryed passes and isprovided with a variable speed driving mean for the drums, thecombination of means to measure the moisture content of yarn passing thedrying drums, means to adjust the variable speed driving meanscontrolled by said measuring means, and means actuated in response tovariations in the speed of the drums to interrupt the operation of saidmeans to adjust the variable speed driving means.

2. In a slasher a rotatable drying drum, means to supply a heatingmedium to said drum. variable speed drive means for said drum, means tomeasure the moisture content of yarn passed over said drum, meanscontrolled by said measurlng mean to adjust said speed varying means,means actuated in response to variations in the speed of the drum torender said adjustment intermittent means to stop said drum and meansoperated by said stopping means to adjust said supp means to reduce theheating medium in aid drum.

3. In a slasher provided with a drying drum, driving means and a supplyof a heating medium therefor, means to vary the speed of said drum,means to stop and start said drmn and means controlled by said stoppingand starting means to prevent operation of said speed varying meansuntil a predetermined period aiter the starting of said drum.

4. In a web drying system, a heated drum over which the web is led,means to measure the moisture content of the web after it ha been dried,means to vary the speed or said drum controlled by said measuring meansand means actuated in response to variations in the speed of the drum tooperate said speed varying means intermittently for periods of timedepending upon the speed of the drum.

5. In a slasher control system wherein the slasher is provided with adrying drum over which the yarn to be dryed is passed and with avariable speed mechanism to drive the drum, the combination of means tomeasure the moisture content of the web after it has passed over thedrum, means responsive to said measuring means to adjust the variablespeed mechanism, and means actuated in response to variations in thespeed of the drums to interrupt the operation of said means to adjustthe variable speed mechanism.

6. In a control system drying means for a web, drive means for saiddrying means, means to' vary the speed of said driving means andtherefore the speed with which the web passes said drying means, meansto measure the moisture content of the web, means to adjust said speedvarying means in response to said measuring means and automatic meansactuated in response to variations in the speed oi the drum to interruptthe operation of said adjusting means so that the speed of the web ichanged in steps.

7. A slasher control system for drying a web comprising in combinationwith a slasher having drying drums, a supply of heating medium therefor,variable speed driving means for said drums, means to stop said drivingmeans and means operated thereby to reduce the speed setting of saiddriving means regardless of the moisture content of the web.

8. The method of controlling a slasher havinga drive means whichcomprises the steps of measuring the moisture content'oi yarn that hasbeen dried by the slasher, controlling the speed or" said drive meansfor said slasher in response to said measurements, and interrupting thespeed controlling operation in timed relation to the speed of theslasher.

9. In a control system for a drying machine having a drying drum andvariable speed means to drive the drum and in which there is a manuallymovable means to disconnect the variable speed means from it source ofpower, the combination of mechanism operated by the manually movablemeans when the variable speed means is disconnected from its source ofpower to positively prevent an increased speed setting of the variablespeed means, and means to delay any change in the setting of thevariable speed means when it is again connected to its source of power.

iii. In a drying system for drying yarn having is access? a drying drumand an exhaust hood positioned above the drum and wherein there isprovided a variable speed means to drive the drum and an adjustablemeans to control the exhaust from the hood, the combination of means tomeasure the moisture content of the yarn being dried, i and meanscontrolled by said measuring means to change the speed of the drivemeans and to adjust the adjustable means in a sense to correctvariations in the moisture content of the yarn.

11. In a web drying machine having a drying portion, means to move theweb therethrough and means to exhaust moisture laden air from adjacentthereto, moisture determining means responsive to the moisture contentof the web leaving said drying portion, means controlled by saidmoisture determining means to vary the effectiveness of the exhaustingmeans and the speed with which the web is moved past said dryingportion, and means actuated in accordance with the speed of the web tointermittently interrupt said controlled means.

12. In a drying machin a. drum over which material to be dried is moved,a fan to force air over said material as it leaves the drum, variablespeed means to drive said drum and variable speed means to drive saidfan, means operated in response to variations in the moisture content ofthe material being dried to simultaneously vary both said driving meansto compensate for changes in the moisture content of the material.

13. In a drying machine, a drum over which material to be dried ispassed, means to supply a heating medium to said drum and means to drivesaid drum, moisture determining means responsive to the moisture contentof the material being dried, means actuated by said moisture determiningmean to vary the speed of said drum and to vary the supply of theheating medium therefor, means to detect variations in speed of the drumand means operated by said last mentioned means to operate said meansactuated by said moisture determining means intermittently for periodsdepending upon the variations in speed of the drum.

14. In a system to dry a web in which there is provided a drying meansfor a web, a means to move the web, a means to vary the speed of themoving means and means to stop and start the speed varying means, thecombination of moisture measuring apparatus to adjust the speed varyingmeans in response to the moisture content of the web that has passed thedrying means, and means to withholdoperation of said measuring apparatusuntil a predetermined period after the speed varying means has started.

15. In a drying machine a rotatable drying drum, means to drive saiddrum and means to vary the speed thereof, means to top the rots.- tionof said drum, means to reduce the setting of the speed varying meansresponsive to operation of said stopping means and means to preventoperation of the speed varying means for a predetermined time after thedrum has been started.

16. In a slasher having a drying drum and a. hood extending thereover,an exhaust duct for said hood, a variable speed fan to draw air fromover said drum through said duct, variable speed means to drive saiddrum, variable speed drive mean for said fan, means to measure themoisture content of yarn passing over said drum, and means to adjustsaid variable speed drive means to speed up the drum and slow down saidfan controlled by said measuring means in response [to a measurementindicating that the yarn is too 17. In a slasher control system in whicha slasher is provided with a rotatable drum over which yarn to be dryedis passed and having drive means for the drum whose speed may be variedbetween given speed limits and having an adjustable means to supply aheating fluid to the drum, the combination of meansto measure themoisture .content of the yarn, mechanism responsive to said lastmentioned means to vary the speed of the drive means for the drum'between its given speed limits, and ineaiis controlled by saidmechanism-and operate upon the reaching of one ofthe speed ,limits ofthe drum to adjust the means to supplythe heating fluid to the drum.

18. Apparatusof the type set forth in claim 17 in which means isprovided to render the opera- ,tion of said supply means discontinuoua19. In a slasher control system having rotatin; drying drums and asupply of steam there- !or, variable speed means to drive said drums,measuring means responsive to the moisture content-of the material driedto vary the speed of said drums between given speed limits, meansoperated by said variable speed drive means to operate said speedvarying means intermittently, means controlled by aid variable speeddrive means and operated in response to the reaching a speed limitof,.said drum to regulate said supply of steam, and means to operatesaid regulating means intermittently.

10. In a system of slasher control, common means at times varying inspeed to drive a plurality of slashers, a variable speed driving meansindividual to each slasher interposed between said common means and theSlashers, means respousive to said common means when it changes in speedto adjust said variable speed, means whereby the speed of the slashersis not altered as the speed of the common means changes, means tomeasure the moisture content of yarn being dried and other meanscontrolled by the in speed to compensate for the variations in dryingeil'ect of each dryer due to said speed changes, and means responsive tothe moisture content of the material being dryed to also adjust theindividual drying effect of each dryer.

22. Ifhe combination of claim 21 including means to render the operationof the last means intermittent.

23. In a control system having a drying machine with drying rolls fordrying a web passing thereover, driving means for the rolls, an electricmotor to vary the speed of the driving means and circuit connectionsbetween the electric motor and a source of energizing current, thecombination of means responsive to a condition of the web which isindicative of the moisture content thereof, and an interrupter driven bythe driving means for controlling the circultconnections jointly withsaid means responsive to the condition of the web.

24. In a system of slasher control, common means at times varying inspeed to drive a .plu-

rality of slashers, individual means to drive each slasher from saidcommon means, mechanism responsive to changes in speed of said commonmeans, mechanism responsive to changes in moisture content of thematerial being .acted upon by said slashers and means jointly operatedby each of said mechanisms to vary the drying eil'ect of said slashersto maintain the moisture content of the material being acted uponconstant.

25. In a system of drier control the combination of means to support anddry material, drive means for said supporting and drying means,measuring means to measure the value of a condition of the materialwhich is indicative of the moisture content thereof and which varies asmeans to stop the drums, and means operated.

the material passe through the drier and which is proportional to thetreatment received, means actuated by said measuring means to vary thespeed of said drive means, and means controlled bysaid drive means andactuated in response to variations in the speed of the drying means tointerrupt the operation of said speed varying means.

26. In a dryer control system wherein there is a dryer having aplurality of drying drums that are driven by a variable speed drivingmeans and means to vary the speed thereof, and wherein th drying drumsare supplied with a heating medium through a regulating means, thecombination of means to measure the moisture content of the web, meanscontrolled by the driving means to adjust the speed varying means insteps proportional to the speed of the drums, and means controlled bysaid last mentioned means and operated upon stopping of the drying drumsto adjust the regulating means in a direction to reduce the supply ofheating medlum.

27. In a web drying machine, a plurality of drying drums, variable speeddriving means, for said drums, means to adjust said driving means, meanto measure the moisture content of a web passing over said drums andoperative to adjust said adjusting means in accordance with the moisturecontent of the web, means controlled by said driving means to render theadjustment tlon. means to synchronize the operation of the adjustingmeans with the speed of the drums,

by, said last mentioned means to reduce the drying effect of the drumswhile they are stopped.

28. In a control system for a drying machine having a plurality of drumsthat have a primary drying eilect on a web to be dried that is passedover them, a means to drive the drums and a means to vary their speed tovary the time the webis in contact with the drums and accordingly varythe primary drying effect of the drums on the web and wherein there is ameans to provide a secondary drying sheet on the web and a means to varythe effectiveness of the secondary drying effect, the combination ofmeans to measure the moisture content of the web, and

varying in speed to drive a plurality of slashers,

a variable speed driving means individual to each slasher interposedbetween the common means and each slasher, means responsive to saidcommon means when it change; in speed to adjust said variable speedmeans whereby the speed of the lashers is not altered as the speed ofthe common means changes, means to provide a drying eflect on the websecondary to that of the drying drums, means to measure a condition ofthe web that i'sindicative of the moisture content of the web, and meansoperated by said last mentioned means to also adjust said variable speedmeans and to simultaneously adjust said mean which provides thesecondary drying eiiect,

30. In a system of slasher control in which each slasher has a pluralityof drying drums over I which a web to be dryed passes, the combinationcomprising common means at times varying in speed to drive a pluralityof slashers, a variable speed driving means individual to each slasherinterposed between the common means and each slasher, means responsiveto said common means when it changes in speed to adjust said variablespeed means whereby the speed of the slashers is not altered as thespeed of the common means changes, a fan operative to produce a dryingeffect on the web secondary to that produced by the drying drums, meansoperative to vary the drying eflect produced by said fan, means tomeasure the moisture content of the web, and means operated by said lastmentioned means to also adjust said variable speed means and tosimultaneously adjust said means operative to vary the drying effect ofthe fan.

31. Ina system of slasher control in which each slasher has a pluralityof drying drums over which a web to be dryed passes, the combinationcomprising common means at times varying in speed to drive a pluralityof slashers, a variable speed driving means individual to each slasherinterposed between the common means and each slasher, means responsiveto said common means when it changes in speed to adjust said variablespeed means whereby the speed of the slashers is not altered as thespeed of the common means changes, a hood located over said dryingdrums, an exhaust duct for said hood, a variable speed fan to draw airfrom over said drums through said duct, variable speed drive means forsaid fan, means to measure the moisture content of the web passing oversaid drum, and means to speed up the drum and slow down said fancontrolled by said measuring means in response to a measurementindicating that the web is too dry.

32. In a system of slasher control in which each slasher has a pluralityof drying drums over which a web to be dryed passes, the combinationcomprising common means at times varyingin speedto drive a plurality ofslashers, a variable speed driving means individual to each slasherinterposed between the common means and each slasher, means responsiveto said common mean when it changes in speed to adjust said variablespeed means whereby the speed of the slashers is not altered as thespeed of the common means changes, means to measure the moisture content0! the web, mechanism responsive thereto to adjust said variable speeddriving means between given limits, adjustable means to supply a heatingfluid to said drum, and means operated in response to the reaching ofone of the limits oi is said variable speed driving means to adjust saidsupply means.

33. In a system of slasher control in which each slasher has a pluralityof drying drums over which a web to be dryed passes, the com.- binationcomprising common means at times varying in speed to drive a pluralityof slashers, a variable speed driving means individual to each slasherinterposed between the common means and each slasher, means responsiveto said common means when it changes in speed to adjust said variablespeed means whereby the speed of the slashers is not altered as thespeed of the common means changes, a fan to force air over the web as itleaves the drum, variable speedmeans to drive the fan, means operated inresponse to variation in the moisture content of the web tosimultaneously vary both said variable speed driving means and variablespeed means to drive 7 the fan to compensate for changes in the moisturecontent of the material.

34. In a system of slasher control in which each slasher has a pluralityof drying drums over which a web to be dryed passes, the combinationcomprising common means at times varying in speed to drive a pluralityof slashers, a variable speed driving means individual to each slasherinterposed between the common means and each slasher, means responsiveto said common means when it changes in speed to adjust said variablespeed means whereby the speed of the slashers is not altered as thespeed of the common means changes, means to measure the dryness of theweb after it has passed over the drums, means responsive to saidmeasuring means to vary the speed of said driving means, and meansactuated in response to variations in the speed of the drums tointerrupt the operation of said speed varying means.

35. In a drying machine, the combination of a drying drum, an exhausthood over said drum, variable speed driving means for said drum,adjustable means to control the exhaust from said hood, means to measurethe moisture content of the web that has been dryed, means operated bysaid measuring means to adjust said variable speed driving means andsaid adjustable means to compensate for variations in moisture in saidweb, a manually movable means to disconnect said variable 'speed drivingmeans from its source of power, mechanism operated in response to thedisconnecting of said variable speed means from its source of power topositively prevent an increased speed setting of said variable speeddrive means, and means to delay temporarily any change in the setting ofthe variable speed means upon the connection thereof to its source ofpower,

36. In a slasher comprising a rotatable drum over which yarn is passed,the combination of means to measure the moisture content ofsaid yarn,variable speed driving means for said drum that is operable betweengiven speed limits. adjustable means to supply a heating fluid to saiddrum, means controlled by said driving means and 0 rated in response tothe reaching of one of the speed limit of said variable speed drivingmeans to adjust said supply means, means to render the adjustment ofsaid variable speed driving means discontinuous, means to stop saidvariable speed driving means, and means operated by said stopping meansto reduce the speed setting of said driving means re-' gardless oi themoisture content of the yarn.

which material to be dried is moved, the co bination comprising a fan toforce air over said material as it leaves the drum, variable speed meansto drive said drum and variabl speed means to drive said fan, meansoperated in response to variations in the moisture content of thematerial being dried to simultaneously vary both said driving means tocompensate for changes in the moisture content of the material, meanscontrolled by said variable speed means and actuated in response tovariations in the speed of the drum to interrupt the operation of thevariable speed means driving said drum, means to stop said variablespeed driving means for said drum, and means operated by said lastmentioned means to reduce the speed setting of said driving meansregardless of the moisture content of the web.

38. In a system of slasher control in which each slasher has a pluralityof drying drums over which a web to be dryed passes, the combinationcomprising common means at times varying in speed to drive a pluralityof slashers, a variable speed driving means individual to each slasherinterposed between the common means and each slasher, means responsiveto said common means when it changes in speed to adjust said variablespeed means whereby the speed of the slashers is not altered as thespeed of the common means changes, means to provide a drying effect onthe web secondary to that of the drying drums, means to measure acondition of the web that is indicative of the moisture content of theweb, means operated by said last mentioned means to also adjust saidvariable speed means and to simultaneously adjust said means whichprovides the secondary drying effect, and means actuated in response tovariations in the speed of the drums to interrupt the operation of saidvariable speed driving means. 39. A web drying machine having aplurality of drying drums over which a web to be dryedis passed, saiddrums having a primary drying eil'ect, means to drive said drums, meansto vary the speed of said driving means to thereby vary the time saidweb is in contact with the drums and accordingly to vary the primarydrying effect of said drums on said web, means to provide a secondarydrying effect on said web, means to vary the eilectiveness of said lastmentioned means, means to measure the moisture content of said web,means actuated by said measuring means to adjust said speed varyingmeans to vary the primary drying effect and to adjust said means varyingthe eirectiveness oi the means for providing the secondary dryingeil'ect, and mean actuated in response to variations in the speed of thedrums to interrupt the operation of said speed varying means.

40. In a drying machine including a drum over which a web of material isto be passed, the combination comprising means to drive said drum, meansincluding a supply line for a heating medium for said drum, a valve insaid supply line, means to measure the moisture content of the web beingdryed, mechanism responsive to said measuring means to vary the speed ofsaid driving means between given speed limits, means controlled by saidmechanism and operated in response to reaching one of said speed limitsto adjust said valve in a direction so that the eil'ect of the heatingmedium will add to that of the drive means to return the moisturecontext of the web toward a given value.

41. In a slasher comprising a rotatabl drum over which yarn is passed,the combination 0 means to vary the speed a; said drum, means to measurethe moistur content of said yarn, mechanism responsive thereto to varythe speed of said drum between given speed limits, a pipe through whichsteam to heat said drum is passed, a valve in said pipe, means tooperate said valve, means operated by said mechanism and operated inresponse to the reaching of one 01' the speed limits of said speedchanging means to adjust the opening of said valve, and means to renderthe operation of said valve discontinuous.

42. In a slasher, the combination comprising a drying drum, means todrive said drum, means to vary the speed of said driving means, means tomeasure the moisture content of yarn passing said drum, means to adjustsaid speed varying means controlled by said measuring means, and meansconnected to said driving means for interrupting the operation oi saidspeed varying means.

43. A slasher control system wherein there is provided a drying drumwith variable speed means to drive the drum and means to disconnect thevariable speed means from its source of power and a supply of heatingfluid for the drum, the combination of measuring means responsive to themoisture content of the yarn that has passed over the drum, anindicating member operated by said measuring means, means operated bythe disconnecting means upon disconnection of the driving means from itssource of power for controlling said measuring means to move saidindicating member, and mechanism operated by said indicating member at apredetermined point in its path to reduce the supply of heating fluid tothe drum.

ANmR E. KROGH.

